Cardio 5 & 6 (Arrhythmias) Flashcards
parasympathetic
calm down
sympathetic
pumped up
What could cause an arrhythmia?
problem with pacemaker, problem with conduction, irritation (like inflammation)
4 Types of Cardiac Rhythms
- Normal sinus impulse formation
- Abnormal impulse formation
- Abnormal impulse conduction
- Escape rhythms
Can cattle have sinus arrhythmia?
no
rS
typical in cattle/category B animals
qR
typical in category A animals
Hyperkalemia and T wave
big, symmetric, pointy T wave
Wandering pacemaker
complex to complex changes in the height of the P wave (very fit, not a concern)
Atrial (supraventricular) premature complex
P wave is generated early, could be negative, buried in T waves (a few different appearances), not terrible, could send you into Afib
Atrial fibrillation in category B animals
no P wave and ventricular response rate is irregular
Atrial fibrillation in Category A animals
no P waves. subtle, low amplitude, lots of variability
Atrial flutter
sawtooth appearance, larger and more consistent amplitude of the ways
Lone atrial fibrillation
can’t find anything else wrong except for the atrial fibrillation (no murmurs, normal rhythm, no imaging abnormalities)
Ventricular Premature Complex
QRS complex is early, QRS-T in opposite direction
Paroxysmal Ventricular Tachycardia
3 or more VPCs occuring so early that they appear in the vulnerable 2nd half of the T wave, can lead to ventricular fibrillation
1st degree AV block
longer PR interval than normal (either took a longer way to travel or something is slowing down the conductivity)
2nd degree AV block (Mobitz Type 1)
progressive lengthening of the PR interval
good, strong sympathetic control of heart rate
2nd degree AV block (Mobitz Type 2)
fixed PR interval but there is damage to the AV node
ST depression
associated with endurance more than damage
PreExcitation Syndromes
different types of bypass tracts but really quite uncommon in animals (very rare in dogs), has a VERY short PR interval, can go in the reverse direction
Left Bundle branch block
blocking conduction to the left ventricle
QRS duration longer than normal
Right Bundle branch block
blocking some of the conduction to the right ventricle
predominantly negative QRS complex
Incomplete Right Bundle branch block
the interventricular septum is thicker so the wave goes in the opposite direction
Hyperkalemia
Long QRS, P wave increases with slight elevation and completely disappears with big elevation, big T wave
increases symmetry
Should you anestheize a dog without a P wave?
No
Hyperkalemia causes abnormal impulse conduction due to ___________
problem with electrolyte concentration
Antiarrythmic drugs
typically go for Phase 0 or Phase 2
ex: lidocaine and calcium channel blockers, beta adrenergic antagonists
